T1D-Anorexia Nervosa Comorbidity

The mean age at anorexia nervosa diagnosis was 16.9 years in females with type 1 diabetes, similar to 16.6 years in females without diabetes. Among females with both conditions, the mean time from type 1 diabetes diagnosis to anorexia nervosa diagnosis was 7.2 years. Females with childhood-onset type 1 diabetes had 64% higher odds of clinically diagnosed anorexia nervosa than matched females without diabetes. Despite elevated relative risk, the absolute risk of anorexia nervosa remained below 2% in females with type 1 diabetes, meaning most individuals did not develop the disorder. The highest-risk birth cohort (1988–1992) showed females with type 1 diabetes had more than twice the odds of anorexia nervosa compared with matched controls. Eating disorder behaviours including intentional insulin omission, self-induced vomiting, and excessive exercise can produce severe hyperglycaemia, diabetic ketoacidosis, and accelerated diabetes complications. The 10-year incidence rate of anorexia nervosa in females with type 1 diabetes was 77% higher than in matched female controls.